Laminated bowling pin



Oct. 6, 1953 FIG. 5

J. L. STEARNS ET AL LAMINATED BOWLING PIN Filed June 8, 1948 INVENTOR JOSEPH L. STEARNS Y CHARLESKH. HOFF N ATTORNEY Patented Oct. 6, 1953 LAMINATED BOWLING PIN Joseph L. Stearns and Charles H. Hoffman, Laurel, Md., assignors, by mesne assignments, to American Machine & Foundry Company, New York County, N. Y., a corporation of New Jersey ApplicationJune 8 1948, Serial No. 31,685

4 Claims. 1

This invention relates to bowling pins, and more particularly to improved laminated bowling pins having better wearing qualities and playing characteristics than laminated bowling pins heretofore known in the art.

The lack of available quantities of hard wood suitable for manufacture into bowling pins, and especially hard maple wood, which is the only type of wood presently approved by the American Bowling Congress, the chief arbiter in bowling, now used in the manufacture of bowling pins, makes it highly desirable to use types of wood which are readily available, and so processed, that bowling pins made therefrom have substantially the same appearance and playing characteristics, especially from the point of View of sound when struck by a ball, resiliency and wearing qualities.

The fact that many available woods, such for instance as soft maple, do not in themselves have physical and wearing qualities which make them suitable without processing for use in the manufacture of bowling pins, is a serious drawback.

been made to produce bowling pins from materials other than hard maple. Substitute materials, such as hard rubber, plastic, soft woods and combinations thereof, have been suggested, but insofar as applicants are aware, none of the pins made from substitute materials has proved to be satisfactory, and hence they have not'been adopted for use in the art.

The present invention provides along sought for solution of this problem because it makes possible the use of woods other than hard maple, or combinations of woods other than hard maple, such as soft maple, or birch, alone or in conjunction with hard maple, in order to form bowling pins which have substantially the same characteristics as conventional hard wood pins, and. which meet specifications approved by the American Bowling Congress with respect to weight. Bowling pins made in accordance with our invention, also have substantially the same spring or resiliency as hard maple pins and give ofi the same desired agreeable sound when struck by a ball.

Our novel laminated bowling pin includes a core section made up of one or more slabs or pieces of wood laminated together by a suitable adhesive. The core may be formed of a relatively soft wood, such as soft maple, and laminations of hard maple and/or other suitable hard wood. Secured to the core, about the sides thereof, are side slabs of compreg. The compregcan be formed of hard maple, or laminations of' hard maple and/or soft wood, or hard maple and/ or soft maple or birch.

The term compreg as used in the wood industry, means the product formed when wood impregnated with a suitable monomer is subjected to heat and pressure whereby the monomer is polymerized and the wood fibres are simultaneously compressed. This is the meaningto be given to compreg as used hereinafter in the specification.

The invention contemplates the use of compreg which is performed prior to its attachment to the core of a bowling pin. For example, a solid core or a laminated core can be formed, and preformed compreg slabs attached thereto in proper arrangement by means of a suitable adhesive. The adhesive employed can be either a room temperature setting or a thermosetting type.

The invention also includes the use of solid lumber side slabs which are impregnated with a suitable impregnant and attached by a suitable adhesive to the comet a bowling pin to form a From time to time in the past, attempts have laminated bowling pin assembly. The laminated slab assembly is then placed in a suitable mold and subjected to heat and pressure which cause a polymerization of the impregnant, and a concurrent compressing and densifying of the fibres of the side slabs which convert them into compreg.

It has been our experience that compreg does not adhere to ordinary wood with the desired permanence unless special Steps are taken to insurethis result. We have found that this difficulty can be overcome by forming laminated compreg such that all laminations but one, which is the exposed face to be attached to ordinary wood, are treated with the impregnant. In other words, one laminate is non-impregnated. Between the non-impregnated laminate and each of the impregnated laminates, is applied a thermosetting adhesive, such as phenol formaldehyde, urea formaldehyde or like adhesive. When the assembly of laminates and adhesive is subjected to heat and pressure, the adhesive and the impregnant are polymerized and the unimpregnated laminate becomes firmly secured to the compreg. This leaves the exposed surface of the nonimpregnated laminate non-compregged, so that when a room temperature setting or a thermos setting adhesive is applied to the exposed face of the non-impregnated laminate, and the latter is placed in sealing contact with ordinary wood, such as the core of a bowling pin, and pressure is applied thereto, the compreg is rigidly and permanently fastened to the core.

It is an object of the invention to provide an improved type of laminated bowling pin having armored sides which greatly increase the life of the pin, and thereby reduce the cost to the operator using pins of this type.

It is a further object of the invention to provide an improved laminated bowling pin having a core constructed of soft maple and having the belly portions of the pin made up of compreg.

It is a further object of the invention to provide a novel laminated bowling pin formed from a laminated core assembly consisting of soft and/or hard maple slabs, and wherein parts of the pin subjected to the greatest wear, are formed of compreg.

The invention also consists in the provision of a laminated bowling pin having a core made up of a plurality of laminates, preferably of soft maple or birch or combinations thereof, and in which the belly portions are formed of compreg resulting from processing slabs of hard maple or slabs of laminated hard maple or laminated veneer assemblies of hard maple and birch.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming a part of this application and in which like numerals are employed to designate like parts throughout the same:

Figure 1 is a view showing one form of a laminated bowling pin made in accordance with our invention and indicating in broken lines a suitable laminated block assembly from which the pin is made.

Figure 2 is a cross-sectional view taken on line 2-2 of Figure 1.

Figure 3 is a view of a modified form of improved laminated bowling pin similar to that shown in Figure 1, except that the core is formed of hard maple.

Figure 4 is a cross-sectional view taken on line 4-4 of Figure 3.

Figure 5 is a side elevation of a modified form of bowling pin having a laminated core formed from soft maple or birch and provided with side ball striking surfaces formed from laminated compreg.

Figure 6 is a view taken on line 6 6 of Figure 5.

Figure '7 is a view indicating diagramatically our improved method of adhering compreg to untreated wood.

Figure 8 is a view illustrating diagramatically a laminated assembly made in accordance with our improved method shown in Figure '7 and Figure 9 is a partial sectional view showing one method of securing a compreg base plug in a bowling pin of the type shown in Figures 1, 3 and 5.

Referring to the drawings, Figures 1 and 2 show one form of our improved laminated bowling pin designated generally l0. Bowling pin l can be turned or shaped in any'known or conventional manner from a laminated slab assembly designated generally 20 and shown in broken lines. Laminated assembly 20 is made up of a core indicated at I5, which can be formed from one or more sections or slabs. As illustrated in Figures 1 and 2, core I is made up of five sections or slabs of soft maple wood, 22,

24, 26, 28 and 30, of a length greater than the length of the finished pin, secured together by a suitable adhesive. The adhesive used can be a room temperature setting resin adhesive. We can also use a thermosetting adhesive, such as phenol formaldehyde, urea formaldehyde or a similar well known synthetic resin or adhesive of the same type. It is essential, however, that the adhesive used be one which will resist fracture or separation of laminates when subjected to impact caused by a rolled ball striking against the pin or by a pin striking against a pin, or for any other reason. The pins must also be capable of being handled in pinspotting machines without rupture of the joints between the several laminates.

As shown in Figures 1 and 2, secured to core assembly 15, formed of core laminates 22-30 inclusive, are side slabs 34 of compreg which have qualities resistant to breakage and fracture when struck by a bowlin ball or one pin striking against another as a result of a ball rolling against pins standing on the playing bed of a bowling alley or falling into the pit.

Although each of the side slabs 34 may be formed initially of compreg, it is within the contemplation of the invention to secure to core l5 hard maple or other wood which has been impregnated with an impregnating resin which, upon subjection to heat and pressure, is converted into compreg. As in the case of the adhesive used for securing core laminates 22-30 together, the same adhesive may also be employed for securing side slabs 34 to core l5. In addition to the heat setting impregnating resin mentioned above, we can also use resorcinolformaldehyde, Dow-Styrene N-99 or other like impregnating resins.

The wood to be converted into compreg can be treated in a well known manner, such for example as follows: Solid lumber side slabs 34 are placed in a suitable treating chamber and subjected to a vacuum for, say, 30 minutes duration, followed by the introduction of a treating solution consisting of a 25% water solution of phenol formaldehyde under a pressure of 155 lbs. per square inch for one hour. These impregnated slabs, following their removal from the treating chamber, can be kiln dried to a moisture content of approximately 10-12%. After drying, they are surfaced on one side and glued to core l5 in pairs with room temperature setting resin glue. square inch are applied for a suflicient time to effect the cure, in order to complete the formation of the laminated pin assembly blank 20, shown in Figure 1.

Blank 2& is then turned to rough shape suitable to allow it to be placed in a mold having a maximum diameter at the belly of the pin of 5%; inch, which is greater than the belly of the finally finished pin. The hardening process in the mold can be accomplished at a temperature of 300-3l0 F. for one half hour at a compressive force sufficient to completely close the mold.

The application of heat and pressure as above set forth, causes polymerization of the impregnant in the side slabs 3d. Simultaneously-with the polymerization of the impregnant, there is a compression of the wood fibres which"densi-' fies the wood and converts the side slabs into compreg. It is preferred but not essential to allow the rough pin blank'to cool' in the mold under pressure before it is removed therefrom. Upon removal from the mold, pin IE] is turned to final size conforming to prescribed bowling specifications.

Pressures of -200 lbs. per

The final pin IE) consists of core- H and compreg sides 35. Pin can then be painted or otherwise decorated in order to conform'with the requirements ofbowling alley proprietors, insofar as color and finish are concerned. Suitable base plugs of fibre and'the like can also be attached thereto aszdesired.

In the form of pin shown in-Figures 3 and 4, the core indicated generally at 40 consists of live laminatespiE, 44, 56, E8- and 50,'formed of hard maple. Securedto core 30 aresides. 52 which can .be formed of compregged hard maple slabs formed in a manner similar to side slabs S t-described'hereinabove. The method of attaching and securing-the side slabs, from which sides52 are formed, to core 40. can'also be the same 'as that employed in securing side slabs 34 to core I5, asshown in Figures 1. and 2.

We have found that it is diflicult to insure a lasting bond between compreg and wood or other material to which it. is attached. Compreg has a glassy, hard surface which makes it difiicult to. glue to other surfaces or to itself. Attempts have been made to roughen one surface of the compreg prior to securing it by room temperature setting or thermosetting adhesives to wood or other material or supporting surface. In the main, however, apermanent bond, using this technique, is difficult to achieve.

:Figures 7 and 8 illustrate our novel method for forming laminated compreg which can be secured to untreated wood whereby a better and more permanent bond results. Figure 7 indicates diagrammatically two impregnant treated superimposed laminates Ell-and fiZ-Which are to be secured together and to an untreated wood laminate 64. Between resin impregnated laminates 60 and 62, is applied a suitable thermosetting adhesive 66, such as a sheet of 'IEIGO glue or other suitable thermoseting synthetic resin or adhesive. The same adhesive 66 is placed between laminates 62 and B4. The stack assembly to be laminated, consisting of. superimposed laminates 60, 62 and 64, is then placed in a press and subjected to heat and pressure, say BOO-350 F. for 35 minutes at a pressure of 2,000 p. s-i. The temperature, time and pressure given are merely illustrative, being values which have been found satisfactory in producing a good grade of compreg which meets the requirements sought for. It is obviousthat other suitable ranges of temperature, time and pressure could be used.

Figure 8 illustrates the finished laminated compreg material in which laminates 60 and 62 have been converted into compreg permanently held together by the polymerized adhesive 66.

As shown in Figure 8, a portion of the layer of the adhesive 66, between compreg laminate 62 and laminate 64, has been absorbed by the nonimpregnated laminate 64, such that the portion thereof adjacent compreg laminate 62, has in elfect been converted into compreg. However, the exposed portion of laminate 64, designated 10, is not compregged.

Laminated compreg, formed in the manner described above, can be readily attached to an untreated wooden surface using either a room temperature setting or a thermosetting adhesive. The wooden surface, to which the laminated compreg is attached, can be a core of a pin, such as cores [5, 48 or 30, shown in Figures 1, 3 or 5, or other suitable wooden surface.

In Figure 5, core Si is formed of laminateda suitable adhesive is placed between the face of the core, to which a laminated compregslabis to be attached, and the untreated face ofthe laminated compreg slab, and this assembly is subjected to'pressure, orheat and pressuradepen'dingupon the type of adhesive .used,,:the jointure between core 80 and the laminatedcompreg. slabs,'from which sides 82 are formed,.treisults in a permanent adherence of the side'sla'bs to the core 80.

In the bowlin pin shown in Figures5- and "6, the laminated compreg sides or coveringelements E2. can'be' formed from either hard maple :veneer or birch veneer, or combinations thereofvas describedsabove in connection with Figures 7 amid A suitable method for forming laminated compreg. sides '82 can consist of subjecting theimpregnated veneer to vacuum "for, say, twenty minutes, followed-by the impregnating solution of, say,.a water solution of phenol formaldehyde: for one hour at 150p. s. i., which results in a dry chemical retention of 10-12%. This material can be kiln dried to-a moisture content of approximately 10%. Alternate layersof-the side slabs of impregnated veneer treated asabove, are arranged, preferably with" the grain at right angles, as shown in Figure 5, in order to increase the strength of the resulting compreg. Between each layer of veneer a'sheet of TEGO filmgli'le or equivalent synthetic resin adhesive 'may' or may not be inserted. As described'above, one laminate 83, of each sldeslab, is not impregnated. The laminated compreg is then formed using the method illustrated in Figures 7 and 8.

Sections or slabs of laminated compreg ofsuitable size are then attached to core 80 which has an octagonal cross section. See Figure 6. While an octagonal cross section is shown in Figure 6, it is obvious that the cross section can be varied as desired. For example, as illustrated in Figures 1-4 inclusive, the cross section of the'portion of cores I n and 40, to which compreg sides or covering elements and-52 are attached, 'isrectangular.

The laminated compreg side slabs, from which sides or covering elements 82 are formed, are glued to core in pairs, one on either side of the core-using a pressure of 250 lbs.- per square inch until the adhesive has set. The temperature, time and pressure given are merely illustrative. Other suitable ranges of temperature, time and pressure could be used. The laminated compreg slabs, which form sides 82, are first attached in the manner described. This process is continued until the core is completely rimmed with laminated compreg slabs, thereby resulting in a laminated slab assembly somewhat similar to that shown in broken lines in Figure 1. Following the completion of the laminated slab assembly, it is turned to form pin 84, shown in Figure 5 in order to conform with standard American Bowling Congress specifications with respect to weight, shape and size.

It is well known that the butt end of a bowling pin is subjected to great wear and tear. From time to time, it is necessary to repair or dress down a pin in order to prolong its life. We have found that a compreg base attached to the butt end of a pin, materially lessens the wear and tear on the butt portion of the pin and therefore increases its playing life. The base can be a compreg insert or plug secured in a longitudinal opening or bore in the butt end of a pin and projecting therefrom. These base plugs can be used in con-. nection with the several forms of pins shown in Figures 1, 3 and 5. In Figure 5 there is shown a base plug 86, formed of several horizontally arranged compreg laminates 88 made of hard maple or other suitable hard wood, or combinations of hard and soft wood. The compreg can be formed in the manner described in connection with Fi ures 7 and 8. Laminate 90 of plug 86, preferably is not impregnated with an impregnant so that it can be more readily joined and adhered to, core 80 when it is adhesively secured in bore 8! of core 80 and subjected to pressure, or heat and pressure, depending upon the type of adhesive used. The portion of plug 86 projecting from bore 81, can be tapered to conform with the exterior taper of the butt end of the pin. In this manner, base plug 86 is permanently attached to core 80.

In Figure 9, base plug 92 is formed with the laminates of the compreg arranged on edge. Base plug 92 can be secured in bore 89 to the core of bowling pin 94 in a manner similar to that described in the attachment of base plug 86 to core 80.

Figure 3 illustrates the use of a solid compreg base plug 96 which is permanently secured to core 40 by means of a suitable room temperature setting or thermosetting adhesive.

The invention above described may be varied in construction within the scope of the claims, for the particular embodiments selected to illustrate the invention are but a few of the possible concrete forms which our invention may assume. The invention, therefore, is not to be restricted to the precise details of the structures shown and described.

We claim:

1. A bowling pin comprising a core, a plurality of laminated compreg covering members adhesively attached to and enclosing an intermediate portion of said core, and with said core forming the bulge portion of said pin, said laminated compreg covering members each having a lamina having an uncompregged inner face, and adhesive securing said face to said core.

2. A bowling pin comprising a relatively soft wood central core shaped at its upper end to form the neck and head end of the pin, and tapered at its lower end to form the butt end of said pin, and a plurality of laminated hard wood compreg covering elements having the grain of alternate laminates substantially at right angles to each other, said covering elements being attached to and encircling the portion of said core between said neck and butt end of said pin; said laminated compreg elements each having a lamina having an uncompregged inner face, and adhesive securing said face to said core.

3. A bowling pin comprising a laminated soft maple central core shaped at its upper end to form the head end, neck and shoulder portion of the pin, and tapered at its lower end to form the butt end of the pin, and a plurality of laminated hard maple and birch compreg covering elements attached to and encircling the portion of said core between said shoulder portion and said butt end, said laminated compreg including an unimpregnated laminate adjacent said core, said covering elements being shaped to form the belly portion of said pin and conform to the taper of said shoulder portion and butt end portion of said core.

4. A bowling pin comprising an unimpregnated wood core shaped at its upper end to form the head end, neck, and tapered shoulders of said pin, and tapered at its lower end to form the butt end of said pin, a plurality of laminated compreg covering elements encircling the central portion of said core between said tapered shoulders and butt end, each of said covering elements having an unimpregnated laminate adjacent said core, and an adhesive rigidly securing said untreated laminate to said central portion of said core.

JOSEPH L. STEARNS. CHARLES H. HOFFMAN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,030,834 Sawyer June 25, 1912 1,088,315 Willson Feb. 24, 1914. 1,197,649 Miller Sept. 12, 1916 1,513,570 Tischer Oct. 28, 1924 1,628,886 Jackson et al May 17, 1927 1,770,388 Bishop July 15, 1930 2,261,264 Luty Nov. 4, 1941 2,354,090 Stamm et al July 18, 1944 2,362,269 Hall Nov. 7, 1949 

